I. Field
The following description relates generally to wireless communications systems, and more particularly to indicating and recovering from a failure of a component carrier in wireless communications systems configured with multiple carriers.
II. Background
Wireless communication systems are widely deployed to provide various types of communication content such as voice and data, Typical wireless communication systems may be multiple-access systems capable of supporting communication with multiple users by sharing available system resources (e.g., bandwidth, transmit power, . . . ). Examples of such multiple-access systems may include code division multiple access (CDMA) systems, time division multiple access (TDMA) systems, frequency division multiple access (FDMA) systems, orthogonal frequency division multiple access (OFDMA) systems, and the like. Additionally, the systems can conform to specifications such as third generation partnership project (3GPP), 3GPP2, High Speed Packet Access (HSPA), High Speed Downlink Packet Access (HSDPA), High Speed Uplink Packet Access (HSUPA), 3GPP long-term evolution (LTE), LTE Advanced (LTE-A), etc.
Generally, wireless multiple-access communication systems may simultaneously support communication for multiple mobile devices. Each mobile device may communicate with one or more base stations via transmissions on forward and reverse links. The forward link (or downlink) refers to the communication link from base stations to mobile devices, and the reverse link (or uplink) refers to the communication link from mobile devices to base stations.
As wireless communications continue to grow in popularity, consumers demand additional features and greater performance. Such features can require high data rates, which can be difficult to reliably achieve within a limited bandwidth, power constraints, and/or interference constraints of a wireless communication system. One option to increase bandwidth (e.g., widen bandwidth), without a large impact on the complexity of radio equipment (e.g., transmitters and receivers), is to implement carrier aggregation. With carrier aggregation, multiple component carriers can be aggregated or grouped to result in an overall wider system bandwidth. Each component carrier can include a complete downlink and uplink with control and traffic channels. Thus, each component carrier can appear as an individual deployment of a wireless communication technology.
Wireless communication devices (e.g., base stations, mobile terminals, etc.) can be configured to utilize multiple component carriers to send data. For instance, a base station and mobile terminal can be configured to respectively transmit and receive data on downlinks of multiple carriers. In addition, the mobile terminal can be configured to utilize a plurality of uplink frequencies on multiple uplink carriers. Accordingly, higher data rates and greater overall throughput can be achieved without a large impact on equipment complexity.